This invention relates generally to steam turbines, and more particularly, to cooling a first stage of a double flow turbine.
At least some known steam turbines include a turbine configuration wherein steam flow entering the turbine assembly is split into two opposite directions using a flow splitter or a tub. In such a configuration, steam contacting the splitter is channeled through opposing turbine nozzle and bucket stages positioned generally in a mirrored relationship on each side of the flow splitter.
Known splitters are fabricated from robust forgings or rings that are coupled together to form the splitter. To withstand the loading that may be induced from the steam flow, generally the forgings are massive structures that are typically coupled together during the final fabrication stage of the steam turbine. More specifically, the splitter halves are coupled together with a plurality of bolts that extend through openings defined in the flanges. The bolts are secured in position with a plurality of locking plates and nuts. During operation, because known splitters are coupled to the turbine portions, and thus rotate with the turbine portions, the bolted connections generate windage losses as the nuts, bolts, and locking plates create turbulence during rotation. Such windage losses adversely affect steam turbine performance and efficiency. In addition, such flow splitter are generally expensive to fabricate because of the amount of material used in fabricating such flow splitters and their associated bolted connections.